St. Cloud Bracing For Power Report

October 20, 1985|By Katherine Long of The Sentinel Staff

ST. CLOUD — In one of the most ambitious and expensive projects to date, the city is planning to juice up its power system so that by 1987 it will be able to provide four times the amount of power it currently distributes.

Decisions on how to improve the plant are in limbo, dependent upon a key engineering study that will be finished within two months.

City officials do not question the need; they have a general idea of what must be done to improve the system, and they say it probably will cost $19 million.

They knew eight years ago the city would need more power. In 1977, the electrical utility plant was peaking at less than 20 megawatts per hour, and officials raised the red flag to warn that major improvements were necessary. Since that time, several generators have been added and stopgap improvements have been made. But there is still a fear that high power demands this winter could strain the system.

Even more serious is St. Cloud's dependence upon a solitary line to Kissimmee's power plant. The line, which soon will be able to handle up to 33 megawatts, is St. Cloud's lifeline. If it fails, the city could be shut down, able only to provide for little more than half its customers in peak demand periods.

With population expected to increase dramatically in the next five years, the city says it has to stop talking about improvements, and roll up its shirt sleeves to begin work on the project.

Improvements for the 50-year-old electrical system are expected to cost $19 million. A final report on the cost, and the best way to complete the project, is due out in the next two months from Black and Veatch, an Orlando engineering firm.

''This project is at the heart of our city as far as growth is concerned,'' said Mayor Bob Renick.

Improvements include building a tie line to a substation in Holopaw, allowing the city to buy directly from Florida Power Corp., building two additional substations and upgrading a third substation, connecting the system with high-voltage power lines, and looping the system to ensure greater reliability during summertime storms.

The tie line allowing the city to buy power directly from Florida Power means the city would avoid switching charges it now pays to other utilities. The city also could make money by selling power to Kissimmee.

Much of the discussion centers on a lot of numbers and technical questions: how much power is used now, how much will be needed in the future, and what size line to build.

Currently, there are seven generators that run on natural gas and diesel power. They can generate up to 34 megawatts.

A tie line running to the Kissimmee Power Plant allows St. Cloud to purchase up to 21 megawatts an hour. A new transformer, scheduled to go on- line this week, will increase that amount to 33 megawatts.

The numbers are important because at peak hours in the summer, city customers demand 40 megawatts to run their homes and businesses. On a cold winter day, the demand jumps to 49 megawatts. Without the new transformer, the city could barely meet the demand for electricity this winter, and the drain on the system could force electrical workers to cut off some customers for a situation known as a brownout.

''We have at least 18 months of leeway -- that's just a guess on my part,'' said Dudley Grimes, Utility Advisory Committee chairman.

The new transformer will increase the amount the city can buy from the Kissimmee plant. Still, it's only a stopgap measure, said Utility Director Ivan Stupal.

''It allows us a time window to put the 230-kilovolt line in,'' he said. ''We're forecasting peaking at 50, 51 megawatts this winter.''

The tie line will cost about half of the total expected cost of expansion, and could bring in as much as 400 million watts, also called megawatts -- enough to power 4 million 100-watt light bulbs.

A volt indicates the potential amount of electricity a line can carry. The watt is a measurement of that electricity.

''The line will directly tie us into services such as nuclear power, plus coal by wire from Georgia,'' Stupal said.

During transmission, lines that carry electricity at high voltage rates lose less power than low-voltage lines. For example, a 69-kilovolt line would lose 10 percent more electrical power than a 230-kilovolt line.

However, the larger line is more expensive. The 12 miles of line needed to tie the power plant into Holopaw would cost $354,500 per mile for a 230- kilovolt line, and $258,200 per mile for a 69-kilovolt line.

Grimes questions the reasoning behind going to the bigger line. Recently, he asked engineers why a 230-kilovolt line was better than the less-expensive 69 kilovolt line, and said he was not satisfied with the answer.

''I'm going to keep asking the question,'' he said. ''I'm not saying it isn't the way to go but I'd like for someone to tell me why.''